The old logic isn't needed anymore since we spawn a new thread.

they finish before shutting down.

the dbd.  (or it will treat it as a slurmctld)

reconnected.

a persistent connection.

as they end in the controller.

returning items in the slurmctld.

handled elsewhere now.

slurmctld.

functions.

slurm_protocol_api

persist_conn code.

handling connections in the fed_mgr.

through to handle persistent connections.

to free to message innards but not the message itself.

know how to connect back when in the federation.

to the common spot in the persist_conn code.

working with the slurmctld.

you will not be able to correctly handle multiple rpc messages.

(The previous code would send one sub-message back instead of a
DBD_GOT_MULT_MSG containing all the responses)

the slurmdbd_msg_t.

Also making calls more generic to handle things better when doing
this in the slurmctld later.